#include "iostream"
#include "vector"
using  namespace std;

int main(char argc ,char *args[]){
    vector<int> arr(5);
    for(int i=0;i<5;i++){
        arr[i]=i;
    }
    cout<<"???";
    for(int i=0;i<arr.size();i++){
        
        cout<<arr[i]<<"  ";
    }
    arr.erase(arr.begin()+4);
    for(int i=0;i<arr.size();i++){
        
        cout<<arr[i]<<"  ";
    }
    return 0;
}